L-isomer of atropine with potent anticholinergic activity at muscarinic receptors in smooth muscle, secretory glands, and the CNS. Reduces GI motility and secretions, bladder spasm, and bronchial secretions. Twice as potent as racemic atropine per mg.
At a glance
Class
Anticholinergic / Antispasmodic
Storage
Store at room temperature below 30°C, protect from moisture
Dosing
Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a
Used for GI spasm and urinary urgency/spasm
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →Safety
Heart rateGI motilityUrine outputPupil size
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →Interactions
No documented interactions.
FAQs
Frequently asked questions
›What is Hyoscyamine?
Hyoscyamine is a anticholinergic / antispasmodic used in pets. L-isomer of atropine with potent anticholinergic activity at muscarinic receptors in smooth muscle, secretory glands, and the CNS. Reduces GI motility and secretions, bladder spasm, and bronchial secretions. Twice as potent as racemic atropine per mg.
›What is Hyoscyamine used for in pets?
Hyoscyamine is used in veterinary medicine for: Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a; Used for GI spasm and urinary urgency/spasm.
›What is the Hyoscyamine dose for dogs?
For dogs, Hyoscyamine is typically dosed as follows — Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a: 0.003–0.006 mg/kg PO/SQ q8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Hyoscyamine dose for cats?
For cats, Hyoscyamine is typically dosed as follows — Used for GI spasm and urinary urgency/spasm: 0.003–0.006 mg/kg PO q8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Hyoscyamine need a prescription?
Yes. Hyoscyamine is a prescription medication and should only be administered under veterinary supervision.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
Find a vet near you →References
References
The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.
Textbooks & handbooks — 5
- Plumb's Veterinary Drug Handbook
- Withrow & MacEwen's Small Animal Clinical Oncology
- Merck Veterinary Manual
- NRC Nutrient Requirements of Dogs and Cats
- Veterinary Pharmacology and Therapeutics (Riviere & Papich)
Clinical guidelines & consensus — 4
- ASPCA Animal Poison Control Center Guidelines
- AAHA Diabetes Management Guidelines
- ASPCA Poison Control Guidelines
- RECOVER CPR Guidelines
Journals & peer-reviewed studies — 2
- EPIC Study (J Vet Intern Med 2016)
- JVIM FAT CAT Study
Regulatory & approvals — 1
- CDSCO Veterinary Drug Approval Registry (1969–2026)
Databases — 1
- Washington State University VCPL MDR1 Database